Disk record and the production thereof.



V. H. EMERSON.

DISK RECORD AND THE PRODUCTION THEREOF.

APPLICATION FILED APR. 15, 1905.

1,950,932 Patented Ja11.21, 1913.

1 19.] EB 54 Fig.2

@QQLLM cacao awvem toz VICTOE H. EMERSON,

OF NEW YORK, N. Y., ASSIGNOR T0 AMERICAN GRAPHOPHONE COMPANY, OF BRIDGEPORT, CONNECTICUT, A CORPORATION OF WEST VIRGINIA.

DISK RECORD AND THE PRODUCTION THEREOF.

Specification of Letters Patent.

Patented J an. 21,1913.

Application filed April 15, 10 5. SerialNo. 255,a0s.

To all whom it may concern:

Be it known that I, VICTOR I-I. EMERSON, a citizen of the United States, and a resident of New York city, New York, have invented a new and-useful Improvement in Disk Records and the Production Thereof, which improvement is fully setforth in the following specification.

This invention relates to the production of commercial sound-records of the disk form. Such records: are now commonly made of a plastic material composed largely of earthy material and shellac. The surface of such records is, on account of the extremely hard particles present inthe earthy material, comparable to a very fine emery wheel, and rapidly wears the point of the reproducingstylus. For this reason, it is the practice to use very cheap reproducing-needles, employing a fresh needle for each reproduction.

Notwithstanding the use of very soft reproducing-needles, recordsof this sort are comparatively shortlived, and the quality thereof begins to show signs of deterioration aftera relatively small number of reproductions. This is due to face, though quite hard, presents numerous very fine points against which the stylus engages and changes the form of the undulations.

The object 7 produce records which will endure a greater number of reproductions without deterioration of quality, and having a surface which will not abrade the stylus, so that a permanent reproducing-point may be employed therewith. It also aims to effect economy 1n production of the record, and to give a smoother reproduction of the recorded sounds free from scraping noises.

In the compositions now in use the shellac is needed in order to give the surface of the record a glazed character. The composition without shellac would beutterly unsuited to the purpose; and, as already stated, even where a large proportion of shellac is used the surface is characterized by the presence of numerous abrading particles. No satisfactory substitute for shellac for this urpose has yet been found, and increased cost has added largely to that of the sound-records.

the fact that the sur of the present invention is to its greatly I have found that a record pressed in a continuous surface of shellac, while not so hard as that of the ordinary composition, is so smooth that a reproducing-point will rub over the same with inappreciable friction, and with very slight wear to either record or point. For the same reason, ing noises heard in the reproduction of ordinary sound-records are much diminished.

The principle of the present invention is, therefore, the production of a sound-record impressed in a continuous film of shellac, which film may be exceedingly thin, thus reducing the quantity of shellac to a minimum. The body of the sound-record may be made of any suitable and cheap inferior stock which of itself may be unsuitable for a smooth record surface, but is capable of being rendered plastic, for example, the earthy compounds now in use with an ordinary binding agent instead of shellac.

In carrying out the principle of the invention, difiiculty has arisen in obtaining a filmy shellac surface free from the gritty particles liable to be present in the stock, but this result has now been accomplished by employing a thin separator-preferably a sheet of fibrous material, as paper-between the shellac surface and the plastic stock composing the body of the tablet. Another di'fiiculty has arisen in impressing the matrix into this shellac surface, in that air would be entrapped between the shellac surface and the matrixesurface, resulting in a bad impression of the undulating record-lines. This difliculty has now been overcome by applying the plastic stock to the rear surface'of the sheet in the form of a .lump placed in the center of the.disk, the effect of which is that, as pressure is applied,

the lump of stock spreads outwardly from the center, whereby the air is driven out from between the matrix and the tablet. In practising the invention it has been found that linen paper of good quality and about five one-thousandths of an inch in thickness will answer the purpose in a satisfactory manner. A sheet of such paper may coated by dipping into an alcoholic solution of shellac, or the latter may be applied with a brush, or otherwise. In this way the paper acts as a carrier for the shellac (permitting the scratch 30 of shellac.

the use of a minimum quantity of the latter) as well as a separator from the material employed for the body of the tablet. To form the sound-record, the paper so treated is laid on the warmed matrix and placed as usual in a suitable press, the stock in the form of an approximately globular lump is laid on the paper sheet at the center of the matrix. and pressure is then applied in the usual way. The stock is applied in a plastic state. being softened at a temperature of about 190 F. A solid and strong tablet results. the union of the several parts thereof not being affected by expansion and contraction due tochanges of temperature.

Although reference has been made above solely to shellac, which gives the best results of any material thus far tried for the purpose, it is obviousthat otherv gums, celluloid, or like materials may be employed in the same way. When shellac is used it is preferable, after drying the sheet, to dip it in a'very thin solution of celluloid, which protects the shellac, and prevents it from I sticking to the hot matrix.

In the accompanying drawingsv I have illustrated the various steps which I preferably employ in practising the process together with the resulting product.

In said drawings, Figures 1 to 6 inclusive are side elevations. Fig. lshows a sheet of paper wit-h a film of shellac thereon; Fig. 2 is the same as Fig. 1 with the addition of a celluloid coaton the shellac; Fig. 3 illus- 35. trates a matrix with a shellac-coated sheet of paper thereon with the shellac surface against the matrix'; Fig. 4 is the same as Fig. 3 with the addition of a mass of inferior plastic composition placed in the' center 40 thereof; Fig. 5 shows the plastic composition in the act of being pressed out'or flattened by a press and spreading from the center outward; Fig. 6 shows the plastic composition spread over the back of the sheet of .45 paper, and the press in the act of forcibly pressing the plastic material, the paper sheet and the shellac together, and impressing the latter into the face of the matrix. Fig. 7

is a perspective view of a tablet with the plastic material, the sheet of paper, the

shellac and the celluloid united together into a complete-record tablet under the action of the heat and pressure in the press.

' In said drawings, A indicates the separator which preferably consists of a sheet of thin paper, and B the coating or film of shellac or shellac-like record. composition,

and 1) indicates a film of celluloid which is sometimes superimposed upon the film B C indicates the matrix, and D indicates a mass or lump of plastic material for forming the main body portion -of the completed tablet. This portion D may be composed of an inferior grade of stock capable of being rendered plastic by heat, and of which. the inferior grade of plastic stock now. used for disk records is anillustration.

The celluloid facing 6 maybe dispensed with if desired. 7 Having thus described my invention, I

claim: I

1. A sound-record composed'of a main body portion of inferior material unsuitable for a smooth record surface and capable of being rendered plastic, a film of glaze material as shellac or the like, an interposed separator between said body portion and said glaze material, and having impressed in said film irregularities corresponding to sound waves.

2. A sound-record composed of a main body portion of inferior material unsuitable for a smooth record surface and capable of being rendered plastic, a film of glaze g5 material as shellac or the like, and an interposed separator of fibrous material between said body portion and said glaze material, and having impressed in said film irregularities corresponding *to sound waves.

3. A sound-record composed of a main body portion of inferior material unsuitable for a smooth record surface and capable of being rendered plastic, a sheet of fibrous material having shellac or the like applied to bothof its surfaces, said shellac serving as a binder between said body portion and one side of said sheet and having irregularities corresponding to sound waves impressed in the other side.

4. A sound-record consisting of a tablet coated or-glazed'with shellac or the like,'and having a separator between said coating and the main body of the tablet, said coating having impressed therein irregularities corresponding to sound-waves, and said main body being of inferior material unsuitable fora smooth record surface and capable of being rendered plastic. 110

5. A sound-record composed of a tablet having a coating or .film ofshellac with a separator of paper or the like between said shellac and the body of the tablet, and having impressed therein irregularities corresponding to sound-waves, and said body being of inferior material unsuitable for a smooth record surface and capable of being rendered plastic.

6. A sound-record composed of a body of suitable stock material, a sheet of paper secured to the same, and a film of shellac or the like secured to said paper, said shellac surface having impressed therein irregularities correspondlng to sound-waves, and said body being of inferior material unsuitable for a smooth record surface and capable of being rendered plastic.

' 7. A sound-record composed of a bod portion containing inferior plastic material 130 unsuited for a smooth record surface, a recrecord material, and a separating sheet between said body portion and said coating to which sheet said body portion andcoating adhere.

8. A sound record composedof a body portion containing inferior plastic material rendered plastic by heat and unsuited for a smooth record surface, a record surface coating of superior shellac-like record material, and a separating sheet between said body portion and said coating to which sheet said body portion and coating adhere.

9. A sound record composed of a body portion containing inferior plastic material unsuited for a smooth record surface, a record surface coating of superior shellaclike record material, and a separating shee between said body portion and said coating to which sheet said body portion and coat- 7 ing adhere under heat and pressure.

10. A sound record tablet consisting of a body portion composed mainly of plastic composition, and a surface composed of a sheet of paper united to the body portion and having an exterior coating of shellac like material.

11. A disk sound record comprising a suitable body portion capable of becoming softened when heated, and a surface composed of a sheet of paper coated with shellac like material and having .a sound-record groove impressed therein.

12. A sound record containing'a sheet of paper comprising a shellac-containing surface carrying a sound record thereon, and a plastic composition to which said sheet is united.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

VICTOR H. EMERSON.

Witnesses:

WM. HACKLAND, JAMES A. MCCONNELL. 

